Plastic stair.



I No. 760,752. PATENTBD MAY24,1904. P. R! PETERSON.

PLASTIC STAIR.

APPLICATION TILED EAR. 21, 1904. v

2 SH BETS- -SHEET 1.

N0 MODEL.

I p g v a, c v

Ifatented May 24, 1904. I

, I PATENT @m a FREDERICKeR. PETERSON, on MALDEN, MASSACHUSETTS.

PL ASTI C sTAm.

SPECIFICATION forming part of Letters Batent no. veer/52, dated May 24,1904.

' application filed March 21, 1904.-

To a) whom it may concern:

Be it known that I, FREDERICK R. PETER- soN, a-citizen ofSweden, and aresident of.

' Malden, in the county of Middlesex and State of Massachusetts, haveinvented certain new and useful Improvements in Plastic Stairs, of whichthe following is a specification.

This invention relates to improvements in plastic or concrete stairwaysand a metal skeleton supporting-frame, as will hereinafter be more fullyshown and described, reference being had to the accompanying drawings,where Figure I is a top plan View of the invem tion, showing the cementremoved from oneof the steps. Fig. 2 is a partial cross-section on theline 2 2 shown in Fig. 1. Fig. 3 is a partial cross-section on the line3 Sshown in Fig. I. Fig. 4 is a side elevation as seen from the openorindependent side of the stairs.

Fig. 5 is a section on the line 5 5 shown in Fig. 1, and Fig. 6 is aside view of the metal supporting-frame as seen from w in Fig. 1.

Similar letters refer to similar parts wherever they occur-on thedifferent parts of the drawings. V

The invention is applicable to what is termed an open or independentfireproof stairway, in which both sides of the stairway are free andexposed, as well as to similar stairways in which one or both sides arelocated adjacent to walls in the building, as may be desired, accordingto the construction or arrangement of the interior walls of thebuilding.

In the drawings,A and B are the respective upper and lower preferablymetal I floor beams to which the upper and lower ends of the frameworkof the stairway are suitably supported in any well-known manner. Themetal framework consists of inclined metal stair-supports C 'D,preferablymade of angleiron, and intermediate such angle-iron supportsis located a central support E, preferably made of T-iron, as shown.Only one such T- iron support is shown; but moremay be used,

according to the width of the stairway.

To the angle-iron D''that is, the exposed side of the stairwayis secureda metal plate or stringer F, which serves tovprotect the Serial No.199,113. -'.No model.)

cement filling G from being defaced or disintegrated, and in Stairwaysthat are exposed on both sides such metal stringer is used on both sidesof the stairway.

For protecting the edges of the cement steps G, I make use of metalangle-moldings H,

which are secured to the center supportingbeam E by means of metaldiverging stays or braces I I, riveted to said beam E and anglemoldings,as shown.- On the exposed side of the stairway I make on saidangle-molding H exposed end of cement'step, as shown. For

the purpose of securing and firmlyholding the cement step in positionrelative to the skeleton an angular end extension H for protecting the Iframework I secure to the angle-molding ex' tensions H suitable metalangular anchorstrips It h, resting on the upper edge of the metalstringer F or riveted thereon, which anchors are embedded in the plasticcement when filled in between the skeleton framework of the stairway.

Gn the unexposed side of the stairway namely, the one adjacent to thewall K in Figs.

land 5 the stringer F maybe dispensed with, as well as the angle-moldingextension H, in lieu of which I secure to the end of the anglemolding Hand side bar C a horizontal metal strap L, which is, attached to thelatter and the angle-bar C by means of a vertical metal strap Z orhanger, preferably riveted to said parts, as shown, and forming asupportingbracket interposed between the angle-molding and bar 0.

After the parts composing the skeleton metal framework have beenassembled the interstices are filled with plastic cement or concrete,which is allowed to set and harden, causing the metal framework'tobe'embedded in the cement, by which a fireproof stairway is produced ofgreat strength and durability.

- Having thus fully described the nature, construction, and operation ofmy invention, I wish to secure by Letters Patentand claim- 1. A skeletonframe for cement-lined stair- Ways consisting of parallel metal sidesupports, one or more intermediateT-beams, an anglemold oredge-protector, diverging braces connecting the latter, and the T-beamand a metal stringer secured to the exposed side of the stairwaysubstantially as and for the purpose set forth.

2. A skeleton frame for cement-lined stairways consisting of parallelmetalside supports, one or more intermediate T-beams, an anglemold or edge-protector, diverging braces connecting the latter and the T-beam, ametal stringer secured to the exposed side of the stairway, and metalanchor-plates secured to the angle-mold and adapted to be embedded inthe cement or plastic material as set forth.

3. A skeleton frame for cement-lined stair ways consisting of parallelmetal side supports,

one or more intermediate T-beams, an anglemold or edge-protector,diverging braces connecting the latter and the T-beam and asupporting-bracket connected to the angle-mold and side support at theunexposed side of the stairway as set forth.

In testimony whereof I have afiixed my signature in presence of twowitnesses.

FREDERICK R. PETERSON.

Witnesses:

ALBAN ANDREN, ALVAH C. STONE.

